Now Trevor Rosenthal is too good to pitch 200 innings

When Trevor Rosenthal was Just The Set-Up Guy this was pretty trivial for me to ignore, but now’s a reasonably good time to come to grips with it: Trevor Rosenthal is a great relief pitcher.

I know, I know—I’m angry about it, too. Among relievers who’ve thrown at least 60 innings he’s fifth in baseball in strikeouts per nine innings and 11th in strikeout-to-walk ratio. He has a slightly unusual repertoire for a shutdown reliever—don’t see a lot of curveballs and changeups from players with his statistical profile—but the experience of watching him is the same, thanks to that 97 mile-an-hour fastball.

But here’s the most important stat: He’s the only member of that K/9 top five with fewer than 28 saves, or 18, or eight, or four. A little further down you’ll get some other set-up man, typically young like Rosenthal (Cody Allen) or left-handed (Charlie Furbush, Jake McGee) or playing behind Mariano Rivera (David Robertson.) But the implication is simple enough: This is what a closer looks like. Even someone like Koji Uehara, who comes by his strikeout rate with an 89 mile-an-hour fastball and a forkball, will eventually begin to accrue saves once it tops 10 per nine innings.

If you are like me—if you were still hoping that the Cardinals would find it both expedient and relatively painless to audition Trevor Rosenthal in the rotation next year—this is bittersweet news.

Jason Motte would have to come back looking exactly like Jason Motte.

If Rosenthal had taken the closer job earlier in the season this might not have made a difference, but he’s still new enough to it that a returning Jason Motte might regain the save-accumulator role.

But Motte’s elbow surgery came late, and he’s unlikely to return early enough to shape the Opening Day bullpen; his return will have to be a reaction to whatever actually happens there, not the action that sets it into motion.

That action starts now, with Trevor Rosenthal’s postseason. And given how he’s pitched, it seems reasonable to assume he’ll pitch well there.

The Cardinals’ rotation would have to be in worse shape than its bullpen.

Great down-the-stretch performances from Michael Wacha and Kevin Siegrist probably cancel each other out, here.

But Siegrist is a left-hander (and came less highly touted), which makes him an imperfect replacement for Rosenthal. And the Cardinals, in any case, have five starters already: Adam Wainwright, Shelby Miller, Lance Lynn, Michael Wacha, and Joe Kelly. (And Carlos Martinez and maybe even Jaime Garcia.)

Trevor Rosenthal is almost certainly better than Joe Kelly, and probably Lance Lynn, too. But he’s also almost certainly better than Edward Mujica, and Seth Maness, and Keith Butler, and the gap there seems to be much easier to see than it is between Joe Kelly playing over his head and Trevor Rosenthal minus a few miles per hour.

Something would have to precipitate taking a big risk.

I don’t see a path toward the Cardinals doing this under their own steam. Adam Wainwright didn’t look like a shutdown reliever, and he looked strikingly like a great starter—and even that took a little doing.

Motte coming back is one of those external forces that could change things. So is an injury in the rotation.

The Cardinals moved Matt Carpenter to second base because second base has been such a black hole that there was nothing left to risk.